The alien came to the library again, shortly before closing time, and quickly found a book.
"May this entity borrow The Complete History of Knitting?"
They always return the book they borrow after five minutes, but the ritual of checking it out seems important to them.
"Of course. Did you bring your card?"
I looked them up, after the first time I saw them for real. They first registered with us over ninety years ago. The senior librarian who first told me about them said I shouldn't stare, or pry.
"Whatever else they are, they are a patron, and should be treated as such," she said. "If they seek knowledge, it is our duty to help them find it."
There isn't an ancient and secret code of librarians, but that is definitely a core part of it. If such a code existed.
I scan the card and the book. "There you go," I say and hand them over. "Please return it within two weeks."
They tilt their head. "This entity will honour your terms."
"Oh! That reminds me, we have updated the terms since your last visit." I hand them the pamphlet we got from the printers last week. "It's mostly about internet usage, but I'll need you to read them and agree."
"These are terms this entity can abide by." They pause. "Is there no requirement to keep your existence secret?"
"Of course not," I say, "we always welcome new patrons."
They stand silent, long enough for me to realise the implications of what I have just said.
"This entity had made an assumption, based on prior experiences on countless worlds, where knowledge is always closely guarded and costly to obtain" they say at last. "You will provide knowledge for free to all who seek it?"
In my mind, I weigh humanity's ignorance of those countless worlds of alien civilisations against the code.
"Yes," I say, "this is a library."
